Caption: Very Large Telescope (VLT) mirror inspection. Engineer carrying out an inspection on the primary 8.2-metre-wide mirror of one of the four VLT units during its construction. He is resting on a support structure and using a microscope to examine the mirror for optical defects. The VLT is an array of four telescopes built and operated by the European Southern Observatory at Paranal in Chile. The combined observations, equivalent to using a 16-metre-wide mirror, make the VLT one of the world's most powerful telescopes. It was built in the 1990s by REOSC, the optical department of the SAGEM group, and began operating in 2001. Photographed in Saint-Pierre du Perray, France.